The present invention relates to avatar animation, and more particularly, to facial feature tracking.
Animation of photo-realistic avatars or of digital characters in movie or game production generally requires tracking of an actor""s movements, particularly for tracking facial features. Accordingly, there exists a significant need for improved facial feature tracking. The present invention satisfies this need.
The present invention is embodied in a method, and related apparatus, for optimizing off-line facial feature tracking. In the method a monitor window is provided that has a visual indication of a plurality of tracking node locations with respect to facial features in a sequence of image frames. The monitor window has a control for pausing at an image frame in the sequence of image frames. The facial features in the sequence of image frames are automatically tracked while the visual indication is presented of the plurality of tracking node locations on the respective image frames. The sequence of image frames may be manually paused at a particular image frame in the sequence of image frames if the visual indication of the tracking node locations indicates that at least one location of a tracking node for a respective facial feature is not adequately tracking the respective facial feature. The location of the tracking node may be reinitialized by manually placing the tracking node location at a position on the particular image frame in the monitor window that corresponds to the respective facial feature. Automatic tracking of the facial feature may be continued based on the reinitialized tracking node location.
In other more detailed features of the invention, the tracking of facial features in the sequence of facial image frames of the speaking actor may performed using bunch graph matching, or using transformed facial image frames generated based on wavelet transformations, such as Gabor wavelet transformations.
Other features and advantages of the present invention should be apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.